Pressure unit



Mardi 19, 194.6. I C, D BURBANK TAL l 2,396,823.

- PRESSURE UNIT original Filed May 25, 1942.

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' Patented Manie, 1946 PRESSURE UNIT p Clifford D. Burbank and Thomas"Harry, Jr.,

`llackson, Mich., assignors, by mesne assignments, to Wilma RhodesRichards, Grand Rapids, Mich.

substituted for abandoned application Serial No. 444,356, May 25, 1942.This application August 30, 1945, Serial No. 613,576

1 Claim.

The present invention relates to pressure units and more particularly toquickly adjustable pressure clamps or vises. The device of the instantinvention is in the nature of a modification of and improvement over thedevice illustrated and described in Patent No. 2,313,361, dated March 9,1943, under which applicants are the exclusive licensees.

The primary objects of the present invention are to provide a pressureunit of the general character above indicated having fewer parts thanare employed in the device of the fio-pending application for patentabove identified; to provide such a device whose pressure rod adjustingsleeve is integrally formed; to provide such a device whose pressure rodadjusting sleeve is provided with an interrupted external thread inscrew threaded engagement with the internal thread of an outer sleevewhereby the movement. of the adjusting sleeve is limited in onedirection; to provide such a device having an improved type of pressurefoot;

and, to provide such a device which is convenient,

and efficient in use and which is reasonably economical in manufacture.

An illustrative embodiment of the invention is shown in the accompanyingdrawing, wherein:

Figure 1 is an elevational view of the pressure unit, here shown as inthe form of a C-clamp;

Figure 2 is an enlarged sectional view thereof on line 2--2 of Figure 1and showing the pressure rod adjusting sleeve within its outer sleevetogether with the longitudinally slidable pressure rod within itsadjusting sleeve;

Figure 3 is a sectional view on line 3 3 of Figure 2;

Figure 4 is an enlarged fragmentary view of the pressure foot of thedevice; and

Figure 5 is a sectional view thereof -on line 5 5 of Figure 4.

Referring then to the drawing wherein like parts of the device shown aredesignated by the same numerals in the several views, the pressure unitillustrated is in the form of a C-clamp, genand a locking roller I6disposed Within the slot i 5 is retained therein by washers I l, I8inserted within the bore of the sleeve. I4 adjacent its opposite ends.The slot I5 which communicates with the bore of the inner sleeve andwhich is greater in depth at one end than the diameter of the lockingroller I6 is of less depth at its other end than the diameter of thelocking roller and it gradually tapers in depth from the larger end tothe smaller end and it provides an eccentricall 7 arranged concavegripping or clutching surface which cooperates with a pressure rod I9 toengage the locking roller and cause the same to lock the pressure rod tothe inner sleeve when the rod is rotated in one vdirection and to freethe rod when the latter is rotated in the opposite direction. Thepressure rod I9 has a sliding t in the bore of the inner1 sleeve andwhen free` to move is capable of longitudinal sliding movement in theinner sleeve and also to rotary movement independently of the innersleeve when the roller I6 is out of locking engagement with the innersleeve and the pressure rod.

The pressure rod I9 has a cross head 20 and is longitudinally slidablyembraced within the sleeve I4 and retaining washers II, I8 and it has areduced portion ZI flared outwardly at its extremity 22. The flaredextremity of the pressure rod I9 .is provided with a concave surface 23and the pressure foot I2 having a concave well 24 within which the ball25 is seated, is secured to the foot end of the pressure rod I9 byfingers 26 struck inwardly therefrom which spacedly embrace the reducederally designated I0, having a jaw II and a rotatably adjustablepressure foot I2 between which a plurality of work pieces may be quicklyclamped under adjustable pressures.

The arm I3 of the C-clamp is provided with a l right hand screw threadedbore within which an externally screw threaded pressure rod adjustingsleeve I4 is screw threadedly disposed.

This sleeve I4 is provided with a longitudinally disposed slot I5eccentrically broached or cross sectionally deeper along one length thanalong itsl opposite length, all as best shown in Figure 3 portion 2l ofthe pressure rod.

The inner end of the pressure rod adjusting sleeve I4 is provided withan interrupted external screw thread or shoulder 2l as shown, providingmeans for unlocking the pressure rod I9 from its adjusting sleeve I4,all as now to be presently described.

Operation ted lines in the same view, effecting a seizure between thepressure rod I9 and its adjusting sleeve I4. Continued clockwiserotation of the cross head 20 effects a rotation of the adjusting sleeveI4 within the screw threaded bore of the arm I3 of the C-clamp I0 tosecure a plurality of work pieces between the jaw II androtatably'adjustable pressure foot I2.

A reversed or counterclockwise rotation of the cross head 20, effects arelease of the binding pressure of the locking roller I6, seized betweenthe pressure rod 19 and its adjusting sleeve I4, when the interruptedportion of the external screw thread Orr shoulder 2,15 of the sleeveVIR* fails to" longer ctn-act with the internalv screw threadA of thebore within the arm I3 of the clamp i or when the adjusting sleeve I4 isrotated from its position shown in full lines in Figure 2 to itsposition shown in dotted lines in the same view, permitting a manualsliding movement of the pressure rod I9 and its presure foot I2I awayfromfthe jaw Il, thereby releasing the'work piecesprevi# ously heldtherebetween and preparatory to the next clamping operation.

The ball 25 seated Within thewell 2 4othe pressure foot I2 and inengagement with the concave surface 22 of the extremity of thepressurerod L9A reduces to a minimum the transfer of torsional' strainupon thepressureird I9 in instances'where clamping pressuresareapplied,` permitting the `effective holding and retention ofnon-parallelsurfaces ofiwork'pieces between the jaw l I and pressurefoot I2 since the pressure foot adapts itself tothe Work piecesclampedftherebetween.

It will thus be seen that the pressure unit herein illustrated'anddescribed is inthenature of aV modification of. and improvement overythe device shown and described in: the above identied Pat- 1 ent No.2,'313`,361,in thatzthe deviceofthe present invention is lcomposed of'.fewer `parts, the; pressure rod adjusting. sleeve is integrallyformedand is provided With an interrupted external thread or shoulderfor limiting its movement Within the outer sleeve for releasing theseized pressure rod and permitting its longitudinal sliding movement andthat an improved type of pressure foot is here provided.

'Whilebutl one specicembodiment of the invention has been herein shownand described, it will be understood that certain details of theconstruction shown may be altered or omitted without departing from thespirit of the invention as the same is defined-by the following claim.

We claim:

Aclutchmechanism comprising an outer sleeve, an inner sleeve havingscrew-threaded engagement with the outer sleeve and movable longitudinally within the latter, the inner sleeve having a longitudinal slottherein which is confined within the cross-sectional area of the innersleeve and which is cross-sectionally deeper along one length thereofthan along its opposite length, the threads of the inner sleeve beingmutilated at one end of the inner sleeve, a locking roller disposed insaid slot, and a rod slidable in the inner sleeve and Operable uponmovement in one direction to cause a locking connection betweenV the rodand the inner sleeve, the mutilated part of the threads of the innersleeve permitting a release of the locking connection when the rod ismoved in the opposite direction.

CLIFFORD D. BURBANK. THOMAS HARRY, JR.

